ProAction (naked) Heads: I E
.100 66 54
.200 136 111
.300 196 154
.400 246 198
.500 276 244
.600 291 254
.700 289 258 ...flowed with 4.060 bore, chamber size
66 w/ 236cc intake
Custom Comp Cam: 214 intake, 218 exhaust - 559 intake lift w/ 1.6
562 exhaust w/ 1.6
-was going to use 1.7-1.8 rocker for extra lift
- lobe center 114
Valve springs: 26918-16 comp
Timing chain: 3153KT
Crank: 6.0L stock
Pistons: Diamond Blower pistons & pins (special made to ProAction Heads)
Block GM 6.0 LQ4

*Goal was to create a 370cu with the MP122H for my 2004 Avv. Its a long story why I'm at this point but I have to decide if I want these pieces. Any help and advice would be greatly appreciated! Thnx R/

 

What's your target CR? With only a 66cc chamber, I'd expect you'd need pistons with some big dishes to keep the CR down for boost.

The intake runner volume is very big for the amount of cfm they flow. It may not matter much though because you'll have the 122 shoving air through them. The exhaust flow #s are great. What are the valve sizes? Are you dead set on the ProAction heads? Personally, I'd look for heads that flowed similar or better, but with a larger chamber and smaller runner.

 

also with that cam you wont see much benefit with those heads

 

Was told that this set up made 707rwhp @ 12psi in a vette...The pistons are 24cc dish and CR shud be down near 9:1 (or slightly lower). As I really am a neophite in this stuff I wasn't set on those heads, but thats what the original builder bot in prep for the project with my deposit. Tho I can argue, this is what I'll prob be stuck with - like it or not - and if I change direction then I'll have to sell them or eat the cost. Lobe center on cam cud be 112 as well, but 114 shud work fine I hope...any thots on lifters? He was gonna go to 1.7 or 1.8, but I've since been told to stay with 1.55-1.6...R/

 

What wud u recommend? Different grind or different heads? R/

 

Well, if you already have the heads then use them. 9:1 is pretty boost friendly. I'd use a cam with a 114 or maybe even wider LSA, not sure about the durations except that supercharger cams typically have a bit more exhaust duration than intake. Stock lifters are fine, as are the Comp stock replacements. Not the Comp-R lifters. Stock rockers are 1.7 already, I'd stick with them.

 

I think quick was saying that about the cam because that amount of lift is fine on stock heads. If you are going with aftermarket heads you can step it up in the lift on the cam to take full advantage of the head flow.

 

I think thats why the builder was planning on going to 1.7 or 1.8, but the guy from ProAction suggested sticking with 1.6....its all gonna be a big experiment as far as I can tell!

 

Cam specs are listed above...custom grind...lemme know what u think. R/

 

I never knew they made 1.6 ratio rockers for an LS1 I think you are spending a lot of money and not taking advantage of your setup. What is the purpose of spending all of that money on a set of rockers when you could just grind a cam for half the amount and get virtually the same valve events and use the stock rockers? Basically what im asking is, besides being different, why?